Silicon micro-electromechanical system (MEMS) resonators can have frequency reference applications, commonly using capacitive detection and actuation principles. For example, small electrodes positioned between the resonator and the support structure can capacitively detect relative gap changes as the resonator resonates. The resonance frequency can then be derived.
There are several disadvantages, however, to such configurations. One disadvantage is that the input and output impedances are high. Additionally, parasitic capacitances have an increasing influence as structure sizes decrease.